JPH0733893B2 - Pulse combustor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse combustor used for heating a liquid or the like by generating heat energy by burning a fuel, and particularly to a structure of a combustion chamber and a tail pipe thereof.

(Prior Art) In a pulse combustor, as shown in FIG. 4, a combustion chamber 1 has a cylindrical shape and a suction port 2 and a tail pipe 3 are provided on a front wall and a rear wall along a center line thereof, and As shown in FIG. 5, there is a type in which the combustion chamber 5 is formed into a casing of a centrifugal pump, the suction port 6 is opened in the tangential direction, and one end of the tail pipe 7 is opened in the center line direction. In these pulse combustors, the part other than the front wall is usually located inside the tank containing the liquid to be heated, so that the spark plug 4 is located on one side of the intake ports 2 and 6. Is provided to penetrate.

(Problems to be Solved by the Invention) Although the cylindrical combustion chamber shown in FIG. 4 can be easily manufactured by welding a pipe material or a plate material, the spark plug 4 is discharged from the intake port 2 at the time of starting. It takes a long time to ignite because the position where the supplied air-fuel mixture is hard to reach, and after the start of pulse combustion, combustion gas (indicated by a dashed arrow) that periodically flows backward from the tail pipe 3 is generated in the combustion chamber 1. Since it is just in the opposite direction to the flowing gas flow, a strong turbulent flow is generated in the combustion chamber 1, which causes irregular combustion of the air-fuel mixture, resulting in partial incomplete combustion, and harmful components (CO, HC) etc. increases.
On the other hand, in the case of the spiral combustion chamber shown in FIG. 5, the air-fuel mixture supplied from the suction port 6 produces a stable vortex in the combustion chamber 5, and the air-fuel mixture is reliably generated in a short time at the time of starting. Spark plug 4
Since the combustion gas that has reached the temperature and is ignited and that flows backward from the tail pipe 7 does not disturb the swirl flow significantly, the air-fuel mixture is stably burned and harmful components in the exhaust gas are reduced, but the spiral-shaped combustion chamber 5 Since it can be manufactured only by using a heat-resistant casting, the manufacturing cost increases. An object of the present invention is to provide a pulse combustor which has a cylindrical combustion chamber, is easy to manufacture, and has a stable vortex flow in the combustion chamber to reduce unburned components in exhaust gas.

(Means for Solving the Problem) For this purpose, the pulse combustor according to the present invention includes a combustion chamber 10 having an intake port 12a and a tail whose one end portion 16a communicates with the combustion chamber 10, as illustrated in the accompanying drawings. In a pulse combustor including a pipe 16, the combustion chamber 10 includes a cylindrical peripheral wall 11 and a front wall 12 that is airtightly integrally fixed to both front and rear ends thereof.
And a rear wall 13, the suction port 12a is provided in the front wall 12, a plurality of the tail pipes 16 are provided, and one end 16a of each tail pipe is provided near the center of the combustion chamber 10 in the center line direction or from this. Is also fixed to the peripheral wall 11 in a substantially radial direction at a position close to the suction port 12a side.

(Operation) The air-fuel mixture supplied from the suction port 12a advances along the center line of the combustion chamber 10, hits the rear wall 13 and is divided into four outward directions, is inverted, and returns along the inner surface of the peripheral wall 11, The doughnut-shaped vortex flow is generated in the entire combustion chamber 10 by repeating the process of turning over the front wall 12 and merging with the air-fuel mixture from the suction port 12a.
Therefore, regardless of the position of the spark plug, the air-fuel mixture reliably reaches the spark plug and is ignited in a short time at the time of starting. Further, since the plurality of tail pipes 16 are provided in the radial direction near the center of the combustion chamber 10 in the direction of the center line or at a position closer to the suction port 12a side than this, the tail pipes 16 periodically flow backward after the start of pulse combustion. The generated combustion gas does not significantly disturb the vortex flow in the combustion chamber 10, so that the air-fuel mixture is stably combusted and the harmful components in the exhaust gas are reduced.

(Effects of the Invention) As described above, according to the present invention, ignition at the time of starting is reliably performed in a short time, harmful components in exhaust gas are reduced, and the combustion chamber has a simple cylindrical shape with both ends closed. Therefore, it can be easily manufactured.

(Examples) The present invention will be described below with reference to examples shown in the accompanying drawings.

First, the pulse combustor as a whole will be described with reference to FIGS. 2 and 3, and the pulse combustor A includes a combustion chamber 10, a tail pipe 16, a decoupler 17, and an exhaust pipe 18, which are integrally connected by welding or the like. The mixing chamber 20 and the valve assembly 24 provided on the suction side of the combustion chamber 10 are the main constituent members. As shown in FIGS. 1 and 2, the combustion chamber 10 is composed of a cylindrical peripheral wall 11 and front and rear walls 12 and 13 which are hermetically welded to both front and rear ends thereof.
The front wall 12 has a reinforcing plate 12c welded by polymerization, and extends outward in a plane to form a circular mounting plate 14. The burner head 12b fixed to the substantial center of the front wall 12 is provided with an intake port 12a concentrically with the peripheral wall 11, and a spark plug 15 is obliquely screwed into the outer peripheral portion of the front wall 12 and the reinforcing plate 12c. It is fixed. The mounting plate 14 is provided with a large number of mounting holes 14a for screwing the pulse combustor A to a tank (not shown) containing a liquid to be heated. The burner head 12 does not have to be the center of the front wall 12.

In the peripheral wall 11 of the combustion chamber 10, the suction port 12a is located slightly from the center in the axial direction.
One end 16a of each of the six tail pipes 16 communicating with the inside of the combustion chamber 10 is radially welded to a position closer to the side, and each tail pipe 16 is parallel to the center line of the peripheral wall 11 (that is, right angle to the mounting plate 14). Is bent backward so that. Decoupler
17 is formed in a cylindrical shape with both ends closed, and is arranged concentrically with the combustion chamber 10 on the rear side thereof. Each of the tail pipes 16 bent as described above approaches the outer periphery of the decoupler 17 and extends to the vicinity of the rear end thereof, then is bent 180 degrees and is again decoupled.
Of the other end 16
b is welded to the front end surface of the decoupler 17 and communicates with the inside of the decoupler 17. One end 18a of an exhaust pipe 18 communicating with the interior of the decoupler 17 is welded to the inside of the decoupler 17, and the exhaust pipe 18 is bent forward so as to be parallel to the center line of the decoupler 17 and approaches the outer periphery of the decoupler 17. Book tailpipe
16 through the mounting plate 14 and the other end 18
The b is led out to the front side, and the penetrating portion is hermetically welded to the mounting plate 14. The decoupler 17 is an expansion chamber having a volume considerably larger than that of the combustion chamber 10, and includes the combustion chamber 10 and the tail pipe 16
Stable pulse combustion is generated in the combusting part consisting of, and the noise accompanying the pulse combustion is silenced by expansion. The decoupler 17 is supported by the mounting plate 14 via a tail pipe 16 and an exhaust pipe 18.

As shown in FIGS. 1 and 2, a mixing chamber 20 having an intake device assembly 24 is screwed and fixed to the outside of the front wall 12 of the combustion chamber 10, and the mixing chamber 20 and the reinforcing plate 12c of the front wall 12 are fixed. The interiors of the combustion chamber 10 and the mixing chamber 20 are communicated with each other via the burner head 12b and the flame trap 21 sandwiched between them. The case 25 of the suction device assembly 24 is provided with a gas suction port 26 in the center and an air suction port 25a around the gas suction port 26. The gas suction port 26 blocks a check valve 27 for preventing backflow from the inside of the mixing chamber 20. A seat plate 28 having a plurality of annular slits 28a arranged annularly and a deflector 29 for increasing the backflow resistance from the inside of the mixing chamber 20 is provided inside the air intake port 25a. Gas inlet
A gas chamber 44 (only a part of which is shown) is shown at 26, and a gas supply pipe (not shown) is connected to the mounting chamber 14.
0, an air chamber (not shown) that hermetically covers the inhaler assembly 24, the gas chamber 44, etc. is provided, and a blower fan (not shown) is connected to this air chamber via an air supply pipe. .

Next, the operation of the present invention will be described with reference to FIG. Gas from the gas supply pipe is supplied to the mixing chamber 20 through the check valve 27, and air from the blower fan is supplied to the inside of the mixing chamber 20 through a large number of slits 28a to form a mixture, which is sucked into the center of the frame trap 21 and the burner head 12b. It is supplied from the mouth 12a into the combustion chamber 10.
The formation dimensions of each part and the characteristics of the blower fan are determined so that the mixture ratio of this mixture becomes a predetermined value suitable for pulse combustion. The air-fuel mixture supplied from the suction port 12a proceeds along the center line of the combustion chamber 10 as shown by the solid line arrow in FIG. 1, hits the rear wall 13 and is divided into four outward directions, and is inverted. Surrounding wall
It returns along the inner surface of 11 and hits the front wall 12 and is turned inward and merges with the air-fuel mixture from the suction port 12a to generate a donut-shaped vortex flow in the entire combustion chamber 10. It should be noted that part of the air-fuel mixture is branched from this vortex and enters each tail pipe 16.

At the time of starting, an ignition device (not shown) is operated for a predetermined time to generate a spark at the inner tip of the ignition plug 15 inside the combustion chamber 10, and the air-fuel mixture is surely ignited in a short time by the donut-shaped vortex.
The pulse combustion is initiated by the action of the resonance system including the combustion chamber 10 and the tail pipe 16 and the suction device assembly 24 that substantially blocks the reverse flow of the air-fuel mixture. After the start of pulse combustion, as shown by the broken line arrow in FIG. 1, high temperature combustion gas periodically flows backward from the tail pipe 16 to ignite the air-fuel mixture in the combustion chamber 10. The combustion gas flowing back into the combustion chamber 10 crosses the flow of the air-fuel mixture along the inner surface of the peripheral wall 11 and merges with the flow along the center line.
Although the vortex flow on the suction port 12a side of the one end portion 16a of the 16 to the peripheral wall 11 is slightly disturbed, the vortex flow near the fixed portion and the rear wall 13 side from this is rather strengthened, and in this embodiment, Since the fixed portion is closer to the intake port 12a side than the vicinity of the center of the combustion chamber 10 in the centerline direction, the donut-shaped vortex in the combustion chamber 10 is not disturbed as a whole. Therefore, the air-fuel mixture is stably burned and the harmful components in the exhaust gas are reduced. Further, since the combustion chamber 10 has a simple cylindrical shape with both ends closed,
It can be easily manufactured by welding pipes and plates.

In the above embodiment, the deflector 29 prevents the backflow to the air chamber side due to the instantaneous pressure increase due to the periodic combustion in the combustion chamber 10, but instead of the deflector 29, the seat plate 28 is used. A flapper valve may be provided which comes in contact with or separates from the mixing chamber 20 side to prevent backflow. If a flapper valve is provided, it is possible to stop the operation of the blower fan except at the time of starting, but intake noise increases slightly and durability deteriorates somewhat. Further, the number of tail pipes 16 is not limited to six as shown in the figure, and the tail pipe 16 may have any bent shape.

[Brief description of drawings]

1 to 3 show one embodiment of a pulse combustor according to the present invention. FIG. 1 is a longitudinal sectional view of a main part, FIG. 2 is a partially cutaway side view, and FIG. FIG. 3 is a view in the direction of III, FIG. 4 and FIG. Explanation of symbols 10 …… Combustion chamber, 11 …… Peripheral wall, 12 …… Front wall, 12a …… Intake port, 13 …… Rear wall, 16 …… Tail pipe, 16a …… One end.

Claims (1)

[Claims] 1. A pulse combustor comprising a combustion chamber having an intake port and a tail pipe whose one end communicates with the combustion chamber, wherein the combustion chamber is hermetically fixed to a cylindrical peripheral wall and front and rear ends thereof. A front wall and a rear wall, the suction port is provided in the front wall, a plurality of the tail pipes are provided, and one end of each tail pipe is provided near the center in the center line direction of the combustion chamber or more than this. A pulse combustor characterized by being fixed substantially radially to the peripheral wall at a position close to the suction port side.